Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D295/00—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms
  • C07D295/22—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms with hetero atoms directly attached to ring nitrogen atoms
  • C07D295/24—Oxygen atoms
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C291/00—Compounds containing carbon and nitrogen and having functional groups not covered by groups C07C201/00 - C07C281/00
  • C07C291/02—Compounds containing carbon and nitrogen and having functional groups not covered by groups C07C201/00 - C07C281/00 containing nitrogen-oxide bonds
  • C07C291/04—Compounds containing carbon and nitrogen and having functional groups not covered by groups C07C201/00 - C07C281/00 containing nitrogen-oxide bonds containing amino-oxide bonds

Definitions

• the present invention relates to a process for the preparation of tertiary amine oxides with a low content of nitrosamines by the reaction of a tertiary amine with an aqueous hydrogen peroxide solution.
• Tertiary amine oxides can be prepared by the process of DE-A 16 94 048, by reacting the tertiary amines in question with an aqueous hydrogen peroxide solution and are used, for example, as solvents for cellulose, polyamides and polypeptides in fiber production. Furthermore, tertiary amine oxides are used as cooxidants for the production of vicinal diols from olefins using osmium tetroxide (cf. Org. Synth. 58 , 43 (1978)). N-methylmorpholine-N-oxide is of particular importance for the uses mentioned.
• tertiary amine oxides are only moderately stable in storage and, as pure substances, tend to release oxygen, they are usually stored and sold in the form of their solutions, generally in the form of their aqueous solutions.
• N-methylmorpholine-N-oxide is usually traded as a 50 to 60% by weight aqueous solution.
• FR-A 26 32638 describes the inhibitory effect of carbon dioxide on nitrosamine formation in the production of the tertiary amine oxides, but in EP-A 320 694 it is found that the addition of carbon dioxide alone is not sufficient for a satisfactory reduction in nitrosamine formation and therefore additionally Reducing agent ascorbic acid must be added to the reaction mixture.
• EP-A 307 184 proposes lowering the reaction temperature for the purpose of reducing the formation of nitrosamine in the preparation of the tertiary amine oxides in the presence of carbon dioxide.
• this process is also uneconomical due to insufficient space-time yields.
• the present invention was therefore based on the object of a simple and economical process for the preparation of tert. To provide amine oxides with a low content of nitrosamines.
• a process for producing tert. Amine oxides with a low content of nitrosamines by the reaction of a tertiary amine with an aqueous hydrogen peroxide solution, which is characterized in that tertiary amines are used as the starting material, the total content of primary and secondary amines is not more than 0.05% by weight.
• Amines with a primary and secondary amine content of less than 0.05% by weight, preferably less than 0.02% by weight, can be obtained from the tert in question.
• Amines which contain these primary and secondary amines due to their production e.g. be obtained by distillation.
• the compounds thus formed can remain in the tertiary amine treated in this way without the subsequent production thereby the tertiary amine oxide is disturbed with the help of a peroxide, in particular with hydrogen peroxide.
• these trapping reagents and their derivatives formed in the reaction with the primary and / or secondary amines can be separated from the tertiary amine by distillation, by extraction, by filtration or centrifugation.
• substances can be used as capture reagents for this purpose that react faster with primary and secondary amines than with tertiary amines and their reaction with these amines is as complete as possible after a short time.
• Such reagents for introducing so-called protective groups on primary and / or secondary amines are described in T. Greene, Protective Groups in Organic Synthesis, pp. 223-287, Wiley Interscience, New York 1981.
• Halogen formates of formula I used to trap the primary and / or secondary amines, the carbamic esters IIa in question form and / or IIb which from the tert. Amine that does not react with these reagents can easily be separated by distillation.
• all types of halogen formates can be used as halogen formates, i.e. those in which Hal is a fluorine, chlorine, bromine or iodine atom and in which R can denote any aliphatic or aromatic radical, owing to their simple preparation and in particular for reasons of cost
• alkyl chloroformate and particularly preferably C1 to C4 alkyl chloroformate are used. These compounds can be prepared in a simple manner by reacting phosgene with the alcohols concerned, for example according to Matzner et al, Chem. Rev. 64 , 645 (1964).
• halogen formamides of the formula III can also be used can be used as an amine scavenger.
• the halogenformamides When the halogenformamides are reacted with primary or secondary amines, the corresponding ureas of the formula IVa are formed or IVb of which the tert. Amine can be distilled off easily.
• all halogen formamides can be used for this reaction, but because of their simple preparation and inexpensive availability, chlorodialkylformamides, in particular chlorodi-C1 to C4-alkylformamides, are preferred.
• chlorodialkylformamides can be prepared by the general method of Rudenko et al, J. Gen. Chem. (USSR) 17 , 2256 (1947) - Chemical Abstracts 47 , 4918 can be obtained by the reaction of phosgene with dialkylamines.
• Carboxylic anhydrides react with the primary and secondary amines to form the relevant carboxamides, of which the tert.
• Amine can be easily separated by distillation. Basically, any carboxylic anhydride can be used to remove the undesired amines from the tert.
• Amine use, but particularly preferably phthalic anhydride and the open-chain or cyclic anhydrides of C2 to C4 mono- and / or dicarboxylic acids, especially acetic anhydride, propionic anhydride, maleic anhydride and succinic anhydride are used.
• the acyl halides form carboxamides when reacted with primary and secondary amines.
• all acyl halides can generally be used to acylate the primary and secondary amines, but for reasons of economy, acyl halides of simple, inexpensive carboxylic acids, in particular C2- to C4-acyl halides, such as acetyl, propionyl and butyryl halides, and benzoyl and phthaloyl halides are preferred .
• Both acyl fluorides, acyl chlorides, acyl bromides and acyl iodides can be used; for cost reasons, acyl chlorides are expediently used.
• Carboxylic acid esters can also be used to acylate the primary and secondary amines. With this acylation method, too, there is in principle no restriction with regard to the carboxylic acid ester to be used.
• Preferred carboxylic acid esters are, for reasons of cost, the esters of benzoic acid, phthalic acid and the esters of C1 to C6 mono- and dicarboxylic acids, in particular the esters of formic acid, acetic acid, propionic acid, maleic acid, succinic acid and adipic acid.
• internal esters of carboxylic acids i.e. lactones
• a preferred lactone for this purpose is ⁇ -butyrolactone.
• the carboxylic acid esters, carboxylic acid anhydrides and acyl halides can be prepared according to the standard methods of Organikum, Organochemisch-Grundpraktikum, 17th edition, pp. 402-408 and 419-424.
• Maleic anhydride and phthalic anhydride are basic chemicals and are produced industrially, for example, by the partial oxidation of butane or butene or xylene according to the processes described in Weissermel, Arpe: Industrielle Organische Chemie, pp. 343-349 and 359-365, Verlag Chemie, Weinheim 1978 produced.
• the hydrogenation of the double bond in maleic anhydride leads to succinic anhydride, its further hydrogenation to ⁇ -butyrolactone.
• the ketenes of the formula V can also be used advantageously in which the radicals R can be the same or different and can represent hydrogen, aryl, especially phenyl and / or C1 to C20 alkyl groups, or their cyclic dimers of the formula VI be applied.
• the ketenes can be produced, for example, from the corresponding carboxylic acids by elimination of water or from the corresponding acyl halides by eliminating hydrogen halide, for example in accordance with the processes of J. March, Advanced Organic Chemistry, 3rd edition, pp. 902 + 916, Wiley, New York 1985 . They are all very reactive and spontaneously add primary and secondary amines to form amides.
• phosgene and its sulfur-containing analogue, thiophosgene are also suitable for trapping primary and secondary amines, whereby form difficultly volatile urea or thiourea derivatives, of which the tert. Amine can be easily distilled off.
• carbonic acid esters of formula VII and pyrocarbonates of the formula VIII the primary and secondary amines react to carbamic acid esters IIa and IIb.
• all carbonic acid and pyrocarbonic acid esters can also be used here, but the inexpensive phenyl, benzyl and C1 to C6 alkyl derivatives are preferably used.
• the carbonic acid esters VII can be obtained, for example, by the process from DE-A 27 43 690, pyrocarbonates, for example by the process according to Howe et al, J. Org. Chem. 27 , 1901 (1962).
• Cyclic carbonic acid esters, such as propylene carbonate can of course also be used to scavenge the primary and secondary amines.
• Non-volatile ureas form during the reaction of the primary and secondary amines with isocyanates
• IX expediently such inexpensive isocyanates as are used as intermediates in the production of crop protection agents or as monomers in the production of polyurethanes and polyureas are used.
• isocyanates are tolylene diisocyanate, hexamethylene diisocyanate, 4,4'-methylene di (phenyl isocyanate), Isophorone diisocyanate, C1 to C6 alkyl isocyanates, phenyl isocyanate and tolyl isocyanate.
• Suitable capture reagents for primary and secondary amines are also phosphinous halides of the formula Xa and phosphinyl halides of formula Xb Phosphonous acid dihalides and phosphonous ester halides of the formula XI in which n denotes 0 or 1, the phosphonyl halides of the formula XII in which n has the meaning given above and the phosphorous ester halides of the formula XIII in which m represents 0, 1 or 2, and phosphoryl halides of the formula XIV in which m has the meaning given above.
• the radical X in these phosphorus-containing trapping reagents can be a sulfur atom or, preferably, an oxygen atom.
• the radicals R can in themselves be chosen arbitrarily. Because of their inexpensive availability, trapping reagents are preferably used in which the radicals R are C1 to C6 alkyl groups or phenyl groups.
• the halogen atom or atoms can also be chosen freely in the case of the phosphorus-containing trapping reagents, but the chlorine compounds in question are generally preferably used.
• Phosphinic acid halides Xa and phosphinyl halides Xb can be prepared according to the methods described in Houben-Weyl, Methods of Organic Chemistry, Volume E1, pp. 245ff, Thieme, Stuttgart 1982 and Volume E2, pp.
• Phosphonyl halides XII can be prepared according to Houben-Weyl, volume E2, p. 315ff and phosphorous acid ester halides XIII by the method of Houben-Weyl, volume E1, p. 313ff.
• Phosphoryl halides XIV can be obtained by the process from Houben-Weyl, Volume E2, pp. 487ff. All of these phosphorus-containing halogen compounds react with the primary and secondary amines to give the corresponding amides in question.
• Reagents which can advantageously be used for the selective derivatization of the primary and secondary amines are also sulfonic acid halides of the formula XV which form the non-volatile sulfonamides in the reaction with these.
• Hal can be fluorine, chlorine or bromine in the sulfonic acid halides; sulfonic acid chlorides are preferably used.
• Such sulfonic acid halides are expediently used as trapping reagents which are inexpensively available on the market, in particular methanesulfonic acid chloride, ethanesulfonic acid chloride, benzenesulfonic acid chloride, toluenesulfonic acid chloride and naphthalenesulfonic acid chloride.
• the esters in particular the C1- to C6-alkyl and phenyl esters of sulfonic acid for trapping the tert. Amine containing primary and secondary amines can be used.
• Such sulfonic acid chlorides and sulfonic acid esters can be produced, for example, according to the methods of Organikum, Organochemische Grundpraktikum, 17th edition, pp. 170-171, 307-313, 545-547 and 557-561, VEB Deutscher Verlag dermaschineen, Berlin 1988 .
• sulfonic acid halides of the formula XVI RS-Hal XVI or sulfinic acid halides of the formula XVII are used, but these are not generally preferred because of their generally higher price.
• Amine oxides tert. If amines are used as starting materials, the content of primary and secondary amines has been reduced to less than 0.05% by weight, preferably to less than 0.02% by weight, by one of the treatment methods mentioned, the nitrosamine content will be the same Way manufactured tert. Amine oxides drastically reduced.
• the starting materials for the preparation of the tert. Amine oxides used tert. Amines are not separated from the primary and secondary amines contained therein in a separate step according to one of the treatment methods described, but instead the trapping reagents for the primary and secondary amines are added to the reaction mixture for the reaction of the tert. Amines to the tert. Amine oxides added and with the tert. Amines incubated before adding the oxidizing agent. In this embodiment of the process according to the invention, essentially nitrosamine-free tert. Get amine oxides.
• all of the above-mentioned capture reagents for primary and secondary amines can be used.
• Particularly preferred in this process variant are carboxylic acid halides, in particular C1 to C4 carboxylic acid halides and benzoyl halides, preferably their chlorides, carboxylic acid anhydrides, in particular C2 to C4 carboxylic acid anhydrides and phthalic anhydride, ketenes and their dimers, in particular C2 to C4 ketenes and their dimers , Sulfonic acid halides, especially C1- to C4 sulfonic acid halides and aromatic sulfonic acid halides such as benzenesulfonic acid halides and toluenesulfonic acid halides, preferably their chlorides and phosphoryl halides, especially phosphoryl chlorides, are used.
• Acetyl chloride, acetic anhydride, ketene, phthalic anhydride, maleic and succinic anhydride, methanesulfonic acid chloride, benzenesulfonic acid chloride, toluenesulfonic acid chloride, dimethoxyphosphoryl chloride and phosphoryl chloride may be mentioned as particularly preferred trapping reagents.
• the capture reagents can be used in stoichiometric amounts with respect to the primary and secondary amines contained in the tertiary amine, but the capture reagents are expediently added in excess with respect to the amines to be separated off. In general, 1.1 to 10 times, preferably 1.5 to 3 times the stoichiometrically required amount of the respective trapping reagent is added to remove the primary and secondary amines.
• Amine starting material can be determined by gas chromatography on the different primary and secondary amines in a conventional manner.
• the tert. Amines with the trapping reagents are generally oxidized to the amine oxides for a period of from 0.25 to 3 h, preferably from 0.5 to 2 h and particularly preferably from 1 to 1.5 h at temperatures from 0 to 150 ° C. , preferably incubated at 20 to 80 ° C and particularly preferably at room temperature.
• the incubation can be carried out at atmospheric pressure or under elevated pressure, in particular the intrinsic pressure of the reaction system, preferably incubation is carried out at atmospheric pressure.
• the reaction mixture can be used without further working up the oxidizing agent for the purpose of converting the tert.
• Amines in tert. Amine oxides are added.
• Amines in the corresponding amine oxides can be used for oxidizing agents which are customary per se, generally an aqueous hydrogen peroxide solution is used, and oxidation processes are used, for example those of DE-A 36 18 352 and DE-A 16 94 048.
• the reaction product can also be worked up in accordance with the per se Methods, for example those of the above-mentioned documents, are carried out.
• the process according to the invention can in principle be used in the production of all tert. Amine oxides from tert. Amines can be applied.
• Such cycloaliphatic, tert. Amines are used in which R1 and R2 together with the nitrogen atom form a 5- to 7-membered, cycloaliphatic ring and R3 is a C1 to C10 alkyl, preferably a C1 to C4 alkyl group.
• Examples of such particularly preferred starting compounds are N-methylpyrrolidine, N-ethylpyrrolidine, Nn-propylpyrrolidine, Nn-butylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, Nn-propylpiperidine, Nn-butylpiperidine, N-methylmorpholine, N-ethylmorpholine Propylmorpholine, Nn-butylmorpholine and N-methyl azacycloheptane called.
• Amines N, N'-C1- to C4-dialkylpiperazines and quinuclidine advantageously as starting materials for the production of tert.
• Amine oxides can be used by the process according to the invention.
• the tertiary amines mentioned are commercially available or can be prepared from the corresponding alcohols by their reductive amination with ammonia, for example by the processes according to DE-A 19 53 263 and US Pat. No. 5,002,922.
• solutions of tertiary amine oxides can be obtained with minimal effort, the nitrosamine content of which, determined by gas chromatography-mass spectrometry coupling or by the method of Krull et al., Anal. Chem. 51 , 1706 (1979) is below 20 ppb.
• NMO N-methylmorpholine-N-oxide
• the 57% by weight NMO solution thus obtained had the following analysis data: Residual NMM content: ⁇ 0.1% by weight Nitrosamine content: ⁇ 20 ppb
• 4.5 mmol of one of the trapping reagents p-toluenesulfonic acid chloride, acetyl chloride, gaseous ketene, methanesulfonic acid chloride and dimethoxyphosphoryl chloride of the formula XIX were used instead of the acetic anhydride used.
• residual NMM contents of in each case ⁇ 0.1% by weight the nitrosamine content was below 20 ppb in all NMO solutions prepared in this way.

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• 1991
  • 1991-12-06 DE DE4140259A patent/DE4140259A1/de not_active Withdrawn
• 1992
  • 1992-11-24 ES ES92119929T patent/ES2084252T3/es not_active Expired - Lifetime
  • 1992-11-24 EP EP92119929A patent/EP0545208B1/fr not_active Revoked
  • 1992-11-24 AT AT92119929T patent/ATE134995T1/de active
  • 1992-11-24 DE DE59205582T patent/DE59205582D1/de not_active Revoked
  • 1992-12-04 JP JP4325404A patent/JPH05246974A/ja not_active Withdrawn
• 1994
  • 1994-08-03 US US08/285,756 patent/US5543515A/en not_active Expired - Fee Related

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